Ventilator for light-projectors or lanterns



8. AND J. W. EWART AND N. W. PRANGNELL. VENTILATOR FOR LIGHT PROJECTORS0R IANTERNS.

APPLICA ON FILED MAR. 25, 1919. 1,337,832. Patented Apr. 20, 1920.

2 SHEETS-SHEET 1- l L I I S. ANEY'J-W. EWART AND N. W. PRANGNELL.

VENTILATOB FOR LIGHT PROJECTORS 0R LANTERNS. APPLICATION FILED MAR. 25,1919.

1,337,832. Patented Apr. 20, 1920.

2 SHEETS-SHEET 2- 1 l 5 d isgsk b,

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U ITED STATES PATENT OFFICE.

SAMUEL EWART AND JOHN WILLIAM EWART, OF LONDON, AND NORM 'iN WILLIAMPRANGNELL, OF MARYLEBON'E, LONDON, ENGLAND.

VENTILATOR FOR LIGHT-PROJECTORS OR LANTERNS.

Specification of Letters Patent.

Patented Apr. 20, 1920.

Application filed March 25, 1919. Serial No. 284,867.

To aZZ whom it may concern:

Be it known that we, SAMUEL EWART and JOHN -WILLIAM EWART, both subjectsof the King of Great Britain, residing at 846, 34:8, 350, Euston road,London, England, and Norman l'l ILLIAM PRANGNELL, a subject of the Kingof Great Britain, residing at 16 Stratford Place, Marylebone, London,Eng land, have invented new and useful Improvements in Ventilators forLightProjectors or Lanterns, of which the following is a specification.

This invention relates to, ventilators chiefly intended for use inconnection with the projectors of electric searchlight equipments, theobject of the said invention being to provide a ventilator, whichaffords a large area of surface for cooling the gases or yapors withinthe barrel or body of the pro ector and effects the deposition of thesolid constituents thereof and in which an upward current or suctionwill be produced which will promote the evacuation or ejection of thegases or vapors resulting from the combustion of the incandescentcarbons or other source of light and which is lightproof or practicallyso.

In the accompanying drawings Figure l is a sectional side elevation of aventilator constructed according to our invention.

Fig. 2 is a sectional plan; and,

Fig. 3 is a sectionalend view of the same.

Figs. at and 5 are respectively a side view and a plan illustrating adetail of the invention drawn to a larger scale than Figs. 1, 2 and 3;and,

Fig. 6 is a section on the line 66, Fig. 4.

The improved ventilator comprises as an essential feature several tiers,preferably three, of tubes, the tubes of the said several tiers beingrespectively indicated by the letters a,.

b. and 0. These tubes are arranged in parallel planes in a casing Z,preferably rectangular in plan and provided with a flange or saddle adesigned to rest upon the barrel or body of the projector, which in thedrawings is indicated bythe letter f, the said projector having in it anopening through which the body (Z projects. dis a packing of a suitablenon-conductor of heat arranged between the saddle e and the body f.

The tubes at in the lower series or tier are of quadrangular section andarranged parallel to one another as shown in Fig. 1, and the tubes Z) ofthe second series or tier have approximately the section of an isoscelestriangle, and are arranged parallel to one an other and to the tubes a,a.

i The tubes 0, of the third series or upper tier of tubes are also ofapproximately the same sectional shape as the tubes 6 and are alsoparallel one to the other.

The tubes a are arranged with spaces 9, between them to allow of theupward escape of the gases, and the triangular tubes 6, are staggeredwith relation to the tubes a, spaces it being left between the adjacenttubes 5 and the tubes a. These spaces 9 and it constitute angular orsinuous passages which allow the escape of the gases or v pors butprevent the passage of light rays. At the ends of the casing (Z, wheresufficient space is not available for complete triangular tubes, angularflanges or baffles 2' are fixed to form spaces it between the outersides of the two end quadrangular tubes a.

If desired an additional tier or tiers of tubes parallel to the tubes aand Z) may be employed. The several tubes which are of sufficient lengthto project completely through holes in the casing cl have fixed to them,before their insertion into the casing, bands 7' provided with flanges jas clearly indicated in Figs. '-l and 5, and when inserting the tubesinto the casing, the sides of the latter are sprung or bent outward to asufficient extent to allow of this, the casing, when the tubes are inplace, springing back against the flanges j 7' on the respective tubesso that the said flanges serve to preventany beam of light escapingbetween the tubes and the edges of the holes in the casing into whichthe said tubes are inserted.

The ends of the tubes which project outside the casing are flangedagainst the said outer face, as indicated at 7c Figs. 4 and 5, theflanges serving to support the casing against inward bulging during theflanging operation.

The tubes are each preferably formed of a single plate bent to thedesired shape, the edges of the said plate, except at the end portions,surrounded by the bands j, being caused to overlap but being leftslightly open, to form gaps, as indicated at Z in Figs. at, 5 and 6. sothat when the ventilator is be 111g moved rapidly through the air, someof the air passing throughthe holes will escape through the gaps Z,thereby producing a certain amount of up-draft between the tubes whichwill tend topromote the evacuation of the gases.

Although no direct light rays can pass between the tubes a, b whenarranged as before. described, the white deposit from the I fumes givenoff by the electric arc will tend to reflect a certain amount of light,and for this reason the third tier of tubes 0, hereinbefore referred tois employed, these tubes as before stated being advantageously arrangedacross the casing d in a direction at right angles to the tubes a, Z).The tubes 0 are provided with flanges j near the ends and are secured tothe casing (Z in the same manner as the tubes a, b, they are alsoprovided with longitudinal spaces or gaps Z, Z through which air canescape. An additional series of tubes parallel to the tubes 0, 0 andstaggered with relation thereto may be employed if desired.

The ventilator casing (Z projects above the level of the tubes 0, asshown in Figs. 1 and 3 and in this projecting portion slots or openingsm, m are formed through which the air can freely circulate. The casingis closed at the top by a cap or hood at having an external flange 0which extends down ward so as to cover the slots or openings m, and isof such dimensions as to allow the ingress of air and the egress of thegases. The said cap or hood, by preference, is formed of a single sheetof metal and the lower edge of the flange 0 is beaded inward, asindicated at g in Fig. 1, so that wet or moisture will not collect uponthe said bead.

To prevent the possibility of any light escaping beneath the edges orflanges of the hood and being reflected on to the barrel 7, a screen orbaflie r is fixed to the casing (Z below the slots m and within the saidhood to intercept such rays. The cap or hood a is preferably held inposition by transverse bolts 5 which pass through the flanges 0 of thesaid cover and through the casing (Z, the said bolts carrying distancepieces t for fixing the position of the cap or hood with relation to thesaid casing.

To the interior of the body or barrel f, screens a, u are fixed whichproject down toward the electric arc on either side of the ventilatorand serve to' collect the fumes and direct them to the said ventilator;or, instead of attaching these screens to the body 7', as shown, theymay be attached to the lower edgeof the ventilator.

Claims: I

1. A ventilator for light projectors or lanterns comprising a pluralityof parallel tubes which extend across the body or casing of theventilator so that the ends are directly open to the air, the tubes ofone tier being staggered with relation to the tubes of the adjacent tierso as to form angular or sinuous passages which 'will allow the escapeof the gases or vapors but prevent the passage of light rays.

2. In a ventilator of the kind claimed in claim 1, the arrangementwherein the tubes of the lower tier are of quadrangular section whilethe tubes of the superposed tier are of triangular section.

v 3. In a ventilator provided with superposed tiers 'of tubes as claimedin claim 1,

the employment of an additional tier of transverse tubes.

4. A ventilator as claimed in claim 1, having parallel tubes formed withlongitudinal spaces or aps for the escape of air from the interiorthereof. V

5hr; ventilator of the kind claimed in claim 1, having parallel tubeswhich are of sufficient length to" project completely through the casingand are furnished at their ends with'fianged bands which formlight-tight joints therewith. V

i 6. In a ventilator of the kind claimed in claim 1, the combinationwith the casing of a cover or hoodarranged to conceal the openingsthrough which the gases orfumes escape.

SAMUEL EWAR'I.

JOHN WILLIAM'EWARI. NORMAN WILLIAM PRANGNELL.

